const arr = [1,2,1,2,3,4,5,3]

//Set
// console.log([...new Set(arr)])

//map + includes
// let res = []
// arr.map(item=> {!res.includes(item) && res.push(item)})

//filter + indexOf
let res = arr.filter((item, index) => {
    return arr.indexOf(item) == index
})
console.log(res)